Device for receiving a combination of two variable volume chambers and a plurality of valves for a supply circuit of an ink jet printing head

Abstract

A device is provided for receiving a combination of two variable volume chambers and a plurality of valves for forming an ink supply circuit for an ink jet printing head. Such a device is formed by a solid one-piece block comprising a plurality of cavities which are disposed radially about a central housing receiving both a piston (P) and a pressure sensor (5). The piston (P) being formed by the stacking of at least two pieces of diameter O 1 and O 2 and two membranes clamped by two flanges, the whole defining two variable volume chambers. This device cooperates with a reservoir block having two compartments between which moves a link connected on one side to an eccentric and on the other to the piston for forming an extremely reliable and compact ink supply circuit.

I claim: 
     
       1. A device for receiving two variable volume chambers and a pressure sensor cooperating with a plurality of valves and valve-restriction pairs, said device providing for a correct operation of an ink supply circuit for an ink jet printing head and a recovery of unused ink at a level of a recovery gutter, wherein said device comprises: a one piece solid block made from a material which resists chemical aggressions, said one piece solid block comprising a central cylindrical housing having a first zone of diameter φ 1  and a second zone of diameter φ 2  in which a piston may move, said piston comprising two stacked parts, the first of said two stacked parts having a diameter O 1  and the second of said two stacked parts having a diameter O 2 , said two stacked parts of said piston defining, within said two zones, by means of two sealing membranes, said two variable volume chambers;   said one piece solid block further comprising:   a plurality of cavities for receiving said valves; and   a housing for receiving said pressure sensor.   
     
     
       2. Device according to claim 1, wherein said piston comprising said two stacked parts comprise in a stacked relationship: a base;   a first membrane clamped by means of a first flange;   a first piece of said diameter O 2  capable of sliding in the zone of diameter φ 2  of the cylindrical housing for defining one of said two variable volume chambers;   a second membrane clamped by means of a second flange; and   a second piece of diameter O 1  capable of sliding in the zone of diameter φ 1  of the cylindrical housing for defining the other of said two variable volume chambers.   
     
     
       3. Device according to one of claims 1 or 2, wherein the housing for receiving the pressure sensor is contiguous with the zone φ 1  of the cylindrical housing. 
     
     
       4. Device according to claim 3, wherein said cavities are disposed radially with respect to the axis of the piston, a first set of said cavities being disposed star-wise and having identical volumes, said first set of said cavities also having bases which are situated in the same horizontal plane, a second set of said cavities being situated in a second plane. 
     
     
       5. Device according to claim 4, wherein said radial cavities open into ducts placing the ends of the valves in communication either with the two variable volume chambers or with other elements of the ink circuit. 
     
     
       6. Device according to claim 5, wherein at least one of said ducts form restrictions. 
     
     
       7. Device according to claim 6, wherein said valves are in line electromagnetic valves. 
     
     
       8. Device according to claim 7, wherein two ends of each of the electromagnetic valves are fitted into two grooves, a sealing being provided by two seals. 
     
     
       9. Device according to claim 8, wherein a flange for maintaining the pressure sensor in position comprises profiles capable of holding a body of the electromagnetic valves at the bottom of the cavity of said electromagnetic valve. 
     
     
       10. Device according to claim 9, wherein said device serves as a base for an ink reservoir block comprising two ink reservoirs placed between said device and a motor block and comprising a passage through which a link passes, one end of said link being connected to the base of the piston and the other end of said link being connected to an eccentric driven by a motor, wherein a maximum length of the link is provided. 
     
     
       11. Device according to claim 10, further comprising cartridge holders for receiving an ink cartridge and a solvent cartridge. 
     
     
       12. Device according to claim 11, wherein said ink and solvent cartridges are removable, the ink being taken at the level of a trocar whose function is to penetrate a pre-perforated membrane.